14.3 Saving into Registers

An alternative to killing and yanking stack entries is using
registers in Calc. Saving stack entries in registers is like
saving text in normal Emacs registers; although, like Calc's kill
commands, register commands always operate on whole stack
entries.

Registers in Calc are places to store stack entries for later use;
each register is indexed by a single character. To store the current
region (rounded up, of course, to include full stack entries) into a
register, use the command r s (calc-copy-to-register).
You will then be prompted for a register to use, the next character
you type will be the index for the register. To store the region in
register r, the full command will be r s r. With an
argument, C-u r s r, the region being copied to the
register will be deleted from the Calc buffer.

It is possible to add additional stack entries to a register. The
command M-x calc-append-to-register will prompt for a register,
then add the stack entries in the region to the end of the register
contents. The command M-x calc-prepend-to-register will
similarly prompt for a register and add the stack entries in the
region to the beginning of the register contents. Both commands take
C-u arguments, which will cause the region to be deleted after being
added to the register.